This movie introduced me to one of my favorite book series, for which I am grateful, and it is beautifully animated and has a great soundtrack. That being said, this movie is terrible. Without a knowledge of the world from the books, it is confusing in the extreme. Who are these people? What are they doing? Why? So many times, why?!? With knowledge of the world from the books it's less of an adaptation than a cobbled abomination! It takes a handful of characters, a few place names, approximately 3 events from one of the books, half a plot point, and then proceeds to fill in the massive gaps with total nonsense.
Some egregious errors include:
Aaron didn't kill his father, who wasn't a king either, sparrowhawk and Aaron set off from roke together and sailed to the far side of earthsea to find cob, theru was burned to the point of severe disability, cob didn't have a castle or henchmen, he lived in the dry land in a state of half death, theru and tenar had nothing to do with the conflict with cob, pretty much everyone besides tenar should have been darker skinned, Aaron's doppelganger isn't a thing...at all... there's nothing in any of the books even close to this, the main locations mentioned and implied are on multiple different islands nowhere near each other not just down the road from each other on the same island.
Some things that were good/correct
The dragons look amazing (even if not totally book accurate), hort town is 75% exactly as it was in the book, the lore about dragons and humans being one is correct, Aaron's sword is half right but cool enough for a pass, sparrowhawks boat, cobs backstory is accurate...and that's it.
It's a halfway decent movie. It's confusing, unsatisfying, and wildly unfaithful to it's source material, I wouldn't give it 2 stars but for it's introducing me to earthsea.